Otto IV of Germany

Otto IV, Holy Roman Emperor (1175-19 May 1218) was Holy Roman Emperor from 1209 to 1215, succeeding Henry VI of Germany and preceding Frederick II of Germany.

First foreign King of Germany
Otto was born in 1175, the third son of Henry the Lion and Matilda of England and a scion of the House of Welf. He grew up in England under the care of his grandfather King Henry II of England, and he became fluent in both German and French while he was at his uncle's court. His uncle Richard I of England made Otto Earl of York as his foster son, but the vassals of Yorkshire refused to let a German rule them, and Otto was unable to assume this title. In September 1196, he was granted the County of Poitou, and he fought under his uncle in his campaigns against Philip II of France; he would be considered an Englishman until 1198.

Welf takeover of Germany
When Henry VI of Germany died in 1198, Otto's brother Philip of Swabia was elected King of the Romans. Because Otto's elder brother Henry V of the Rhine was on a crusade at the time, Richard of England and princes opposed to the Hohenstaufen dynasty sought Otto to be the new Holy Roman Emperor. On 9 June 1198, he was elected King of Germany by his partisans, and on 12 July he was crowned in Aachen after taking over the city. Philip of Swabia allied with King Philip II against Otto and Richard, and Richard was sadly killed in 1199 at Chalus; John of England supported Otto after this. On 21 June 1208, Philip of Swabia was murdered, and on 21 October 1209 Otto was crowned Holy Roman Emperor.

Downfall of the Welfs
However, he annulled the Concordat of Worms, restoring free investiture to the Holy Roman Emperor. On 18 November 1210, Otto was excommunicated as a result, and Frederick II of Germany made his way up through Italy to seize the throne for himself. Philip's support of Frederick II led to Otto renewing an alliance with England against France, culminating in the 1214 Battle of Bouvines. Philip defeated Otto in that battle, and Frederick took Aachen and Cologne. In 1215, he was forced to abdicate the imperial throne, and on 19 May 1218 he asked his priests to mortally expiate him in atonement for his sins as he died of illness. The abbot flung him to the ground as he confessed his sins, and the priests beat him bloodily to death, bringing an end to the first and last Welf emperor.